public class Example4_9 {
    public static void main(String args[]) {
	SIM simOne = new SIM(12889776509L);
	MobileTelephone mobile = new MobileTelephone();
	mobile.setSIM(simOne);
	System.out.println("手机号码:"+mobile.lookNumber());
	SIM simTwo = new SIM(15967563567L);
	mobile.setSIM(simTwo);
	System.out.println("手机号码:"+mobile.lookNumber());
    }
}
